c@225: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
c@225: 
c@225: /*
c@225:     QM DSP Library
c@225: 
c@225:     Centre for Digital Music, Queen Mary, University of London.
c@309: 
c@309:     This program is free software; you can redistribute it and/or
c@309:     modify it under the terms of the GNU General Public License as
c@309:     published by the Free Software Foundation; either version 2 of the
c@309:     License, or (at your option) any later version.  See the file
c@309:     COPYING included with this distribution for more information.
c@225: */
c@225: 
cannam@489: #ifndef QM_DSP_FILTER_H
cannam@489: #define QM_DSP_FILTER_H
c@225: 
c@434: #include "base/Restrict.h"
c@434: 
c@417: #include <vector>
c@225: 
c@417: class Filter
c@225: {
c@225: public:
c@417:     struct Parameters {
c@417:         std::vector<double> a;
c@417:         std::vector<double> b;
c@417:     };
c@417: 
c@417:     /**
c@417:      * Construct an IIR filter with numerators b and denominators
c@417:      * a. The filter will have order b.size()-1. To make an FIR
c@417:      * filter, leave the vector a in the param struct empty.
c@417:      * Otherwise, a and b must have the same number of values.
c@417:      */
c@417:     Filter(Parameters params);
c@417:     
c@417:     ~Filter();
c@225: 
c@225:     void reset();
c@225: 
c@417:     /**
c@417:      * Filter the input sequence \arg in of length \arg n samples, and
c@417:      * write the resulting \arg n samples into \arg out. There must be
c@417:      * enough room in \arg out for \arg n samples to be written.
c@417:      */
c@434:     void process(const double *const QM_R__ in,
c@434:                  double *const QM_R__ out,
c@417:                  const int n);
c@225: 
c@417:     int getOrder() const { return m_order; }
c@417:     
c@225: private:
c@417:     int m_order;
c@417:     int m_sz;
c@417:     std::vector<double> m_a;
c@417:     std::vector<double> m_b;
c@417:     std::vector<double> m_bufa;
c@417:     std::vector<double> m_bufb;
c@417:     int m_offa;
c@417:     int m_offb;
c@417:     int m_offmax;
c@417:     bool m_fir;
c@225: 
c@417:     Filter(const Filter &); // not supplied
c@417:     Filter &operator=(const Filter &); // not supplied
c@225: };
c@417:     
c@225: #endif